Dear Doc: Wise to give MMR vaccine if child has allergy to eggs?

Dear Dr. K.: My daughter is allergic to eggs. They cause her to have hives. Should we avoid the MMR (measles-mumps-rubella – formerly known as German measles) shot?

The old answer to your question is a qualified “no.” The new answer is an unqualified “no.” But, let me explain.

Three primary vaccines exist that are produced using egg embryo fibroblasts. Because of this milieu, there is some – at least theoretical – potential for the vaccines to elicit an allergy in a person with egg allergy. The three are MMR, flu and yellow-fever vaccines. Of these, the MMR has the least amount of egg binders/fillers (technically excipients).

Prior to a fairly recent study done at Duke University in cooperation with Johns Hopkins, children with egg allergy were treated in several ways: In some cases, the administration of the MMR was delayed until the egg allergy and/or the allergy testing to egg diminished; in other cases, the children were tested with the allergy vaccine itself. If the test was positive, the vaccine administration was delayed until the test was negative. If the vaccine test was negative, then the MMR was given.

The Duke/Johns Hopkins study looked at a large group of children with a clinical history and skin-test confirmation of egg allergy. Testing for allergy to the MMR vaccine was positive in some and negative in others. All the children in this study were given the MMR vaccine; none had an allergic reaction. Therefore, based on this study, your daughter should go ahead and get the MMR shot.